The present invention relates generally to machines for applying a glazing, icing or other similar coating to doughnuts, pastries and other comestible articles. The present invention is particularly directed to machines for applying such coatings to fully cooked and pre-frozen doughnuts that have been thawed, heated and glazed shortly or immediately prior to sale to achieve a xe2x80x9cfreshxe2x80x9d quality.
Doughnuts, while traditionally a morning food to be consumed in conjunction with beverages such as tea or coffee, have become a popular snack item that can be consumed at virtually any time of the day. Many shops and fast service outlets are devoted solely to the manufacture and sale of fresh doughnuts. Other commercial establishments, such as full service grocery stores, smaller convenience stores, fast service and limited menu restaurants, gas stations and even bookstores, have attempted to satisfy the public demand for such food items. The manufacture of fresh doughnuts requires a significant investment in specialized machinery and considerable knowledge and skill unlikely to be possessed by most workers at these other commercial establishments. Further more, the specialized machinery and equipment requires daily cleaning that requires significant non-productive time by personnel. To avoid the substantial investment in equipment and personnel, these other commercial establishments have generally resorted to the sale of doughnuts and pastries that are prepared off-site.
Doughnuts and pastries have a rather short shelf life due principally to the escape of moisture from the cooked article. Applying a glazing, icing or other similar coating over the entire exterior of the article not only enhances the taste, but also seals in a desirable level of moisture that can modestly extend its shelf life. Refrigeration of the finished doughnuts can further extend the shelf life, but almost immediately eliminates the hot, fresh quality desired by consumers. Thus, even well cared for goods often do not match the appeal of the fresh products produced on site at dedicated shops and outlets. There is also the additional problem for conventional off-site production of quickly responding the changes in consumer demand, often on a day-to-day basis. Any unsold products must generally be discarded when the shelf life is exceeded, which can substantially negatively impact the overall profit to be earned from the product.
One alternative that has been employed with modest success in the use of bakery products, particularly raised doughnuts that are cooked and frozen at a central manufacturing facility. The frozen bakery products are delivered to commercial retail establishments in a frozen condition where they can be stored for considerable period before use. The products are typically quickly thawed and heated rapidly to recapture the fresh quality that the consumer desires, and then finished by the addition of a glaze or icing. The batches can be sized to meet the variations in consumer demand on a daily or even hourly basis. While existing apparatus allows retailers to quickly and continually produce desired quantities of xe2x80x9cfreshxe2x80x9d doughnuts through the day, the application of glazing and icing to the products presents an especially messy problem that still generally requires a measure of skill on the part of the worker, requires considerable cleaning time and effort, and is often very wasteful of the glazing or icing
Thus what is needed is a machine that is simple to use and easy to clean to apply the desired amount of glaze, icing, or other finishing fluid onto previously heated doughnuts, pastries or other food products with little waste. It is preferable for the machine to be largely automated so that the entire operation can be operated by one person. It is also desirable that the machine occupy as little floor space as possible, and be reasonably priced so that the cost can be recovered within a reasonable time from the enhanced profits derived from the food products produced by the machine.
Additionally, it is important that the machine be safe to operate, and provided with very simple and clearly marked controls so that the machine is operable by lower level employees. Finally, it is important that the food products produced by the machine have excellent flavor, freshness, and other characteristics likely to enhance customer appeal.
A machine according to the present invention includes a floor-supported base that can include wheels to permit the apparatus to be easily moved from place to place to permit cleaning, servicing, and the like. The apparatus mounted on the base includes an oven that is generally intended for reheating previously cooked food products but can also be an oven for cooking or completing the cooking process of the food product in question. The oven generally includes a heater mechanism with associated temperature controls. The oven also includes a conveyor for conveying food products through the oven from an intake to an output. A food finishing area is located below the oven where the food products heated in the oven are finished with glaze, icing or the like. A chute is provided that directs the heated food products from the oven output to the food finishing area. A discharge area is located at an output of the food finishing area for receiving food products subsequent to their finishing.
A drive mechanism is connected to the base and includes first couplings positioned in the food finishing area and discharge area. Supports, preferably in the form of rods, are also fixed to the base so that they project outward adjacent to each of the drive mechanism first couplings. Two conveyor units are provided, one being located in the food finishing area and one in the discharge area. Each conveyor unit includes a chassis, a driving component having a second coupling, and a porous belt supported on the chassis and driven by the driving component. Each conveyor unit chassis is mounted on the supports so that the second coupling on the driving component engages one of the first couplings of the drive mechanism to provide power from the drive mechanism to the conveyor units"" driving components. Each of the conveyor units is individually releasable as a unit from the supports to facilitate cleaning of the conveyor units.
The conveyor unit in the finishing area receives the heated food products from the chute connected to the oven output and transports the food products through the finishing area. A drawer unit containing a heated water bath is provided below the finishing area. The water bath is intended to receive commercial containers of pre-prepared finishing such as glaze, icing or the like, which is heated by the water bath to a temperature that will facilitate the distribution of the icing or glaze in a fluid state over the food products as they pass through the finishing area. A pump, preferably a peristaltic pump, is provided that has an inlet, which can be submerged in the container of pre-prepared finishing fluid, and has an outlet connected to a distributor located above the conveyor in the finishing area. Finishing fluid, transported by the pump from the commercial supply container to the distributor, falls from the distributor in a predetermined pattern over the heated food products as they are transported through the finishing area by the conveyor unit.
Any excess finishing fluid falls through the porous belt and is directed by a guide positioned below the finishing area conveyor unit back into the supply container. The guide situated below the finishing area conveyor unit can also including a slide forming a portion of the chute that introduces food products onto the finishing area conveyor unit. An air knife can be provided above the finishing area conveyor unit, directly down stream from the distributor, for removing excess finishing fluid from the food products passing through the finishing area. The air knife also initiates a cooling of the glaze, icing or other food finish that traps the desired amount of moisture in the food for maintaining its fresh quality for some period of time. The cooling continues as the food products are transferred to the conveyor unit located in the discharge area. By the time the food products have substantially completed the transport through the discharge area, the finish provided by the glaze or icing is sufficiently set so that the food products can be manipulated by hand onto display racks or trays, or placed in packages ready for the consumer to purchase.
In a preferred embodiment, the conveyor chassis of the two conveyor units in the finishing area and the discharge area includes a pair of parallel side plates. The side plates are secured to each other in parallel relation by a pair of tubular elements having open ends forming channels. The tubular channels are of sufficient size to slidably receive the support rods that project outward from the base adjacent to one of the drive mechanism""s first couplings. The distal end of the support rods supporting each of the conveyor units are preferably tapered, and at least one of the support rods includes an engagement element preferably taking the form of a groove adjacent to the distal end. Each of the conveyor units includes a second engagement element for cooperatively engaging the first engagement element to retain the conveyor unit chassis on the supporting rods. The second engagement element preferably takes the form of a latch engagable in the groove, the latch including a handle to permit manual disengagement of the latch from the groove. The latch preferably also includes a stop permitting the latch to only come in tangential contact with the support rod tapered end portion.
Each of the first couplings on the drive mechanism preferably takes the form of a stepped surface or key. The driving component included in each conveyor unit preferably takes the form of a shaft that is coupled to the side plates by suitable journals. A stepped surface is provided on the end of the shaft forming the driving component that can engage the stepped surface on the drive mechanism when the conveyor unit is fully situated on the support rods. A plurality of toothed sprockets are fixed to the shaft forming the driving component that engage in the porous belt for driving said belt. The porous belt preferably takes the form of an open mesh wire belt engaged on the toothed sprockets of the driving component. One or more additional idler shafts can be provided as a part of each conveyor unit to further support the porous belt for movement relative to the conveyor unit chassis.
The conveyor units of the present invention are preferably sized to be easily handled by one person, and can be quickly removed from the machine as a unit to be cleaned in any commercial sink. Any overflow of the glaze, icing or other finishing fluid is continuously returned to the commercial container in which it was initially supplied. At the completion of operation, the unused glaze or icing can be recovered by simply placing the original lid on the commercial container in which it was supplied. The container can be removed from the water bath to suitable storage for subsequent use. The hot water in the water bath can be used to flush through the pump and related tubing to quickly clean the finishing fluid distribution system. Other elements of the machine are similarly designed with ease of cleaning in mind so that clean-up of the machine at the end of the day can be accomplished in a short time, typically in a half-hour or less.
Additional features of a machine of the present invention will become apparent to those skilled in the art from a consideration of the following description of a preferred embodiment. Throughout this description and including the claims it should be understood that the use of the term xe2x80x9cfirstxe2x80x9d with reference to any structure is not to be taken as requiring the presence of a xe2x80x9csecondxe2x80x9d of that same or similar structure. Throughout this description and including the claims it should also be understood that the use of a term referencing a structure in the singular does not preclude the repeated or plural presence of that structure, and vice-verse. The following description should be considered in relation to the included drawings that are intended to depict the best mode of carrying out the invention as presently conceived.